A 47 year old man is described who developed pathologyproven Creutzfeldt-Jakob disease (CJD) 38 years afterreceiving a low dose of human derived growth hormone(hGH) as part of a diagnostic procedure. The patientpresented with a cerebellar syndrome, which is compatiblewith iatrogenic CJD. This is the longest incubation perioddescribed so far for iatrogenic CJD. Furthermore, this is thefirst report of CJD after diagnostic use of hGH. Since thepatient was one of the first in the world to receive hGH,other cases of iatrogenic CJD can be expected in the comingyears............snip...........tss